you must first get the silph scope and defeat Erika, the leader of Celadon City gym.
complete silp co tasks
Silph Co.
Find him outside the Pokemon fan club in Vermilion. Then go to Silp co. in Saffron and talk to him. He will ask you to pick a stone. Green: Treecko Red: Torchic Blue: Mudkip
That TM is in silph co.
You need to get the Silph Scope from Silph Co.
You get it as a prize from beating your Rival at Silph Co.
Serebii.net has all the answers. Go to Silph Co. and talk to the president of Silph Co.
You get it from a rocket from the rocket hideout in Celadon city.
Continue with the game and eventually he will fall asleep and will not be in front of the door.
go to silph co. its on floor 5 then once you have it go to floor 9
Silph Co. is located in Saffron City. In order to enter the building you must have beaten team Rocket at Rocket Game Corner in Celadon City, and the Pokemon Tower in Lavender Town.
I have blue, so I might be wrong... Beat Gary in silph Co. and talk to the person in the room.